Carburetor



Oct. 25, 1932. SMITH 1,884,315

CARBURETOR 3 Sheets-Sheet 1 Filed Nov. 7, 1928 Ida Oct. 25, 1932.

5 Sheets-Sheet, 2

F. H. SMITH CARBURETOR Filed Nov. 7. 192a Oct. 25, 1932.

F. H. SMITH CARBURETOR Filed Nov. 7, 1928 5 Sheets-Sheet 3 a more thorough and complete breaking up or- Patented. Oct. 25;, 1932' UNITED STATES FREDERICK HUGH- summon snnnwoon msn, no'rrnvezinmnnenann ABBUBETOB Application filed November 7,1928, Serial 110.317,?23, and iniGr ea't Britain May 1, 192a:

in construction and operation than carburet-- ors heretofore employed or proposed, will produce under all conditions of working a vaporization of the petrol orother liquid fuel and also produce a more complete and intimate mixtureof such petrol with air than is possible with such known or proposed car- 11116 CG' of lhgure 4.

buretors.

Other objects of the invention, attained by the realization of, the before mentioned objects, are to obtain easy and practically instantaneous starting under all conditions of an engine to which the improvedcarburetor is applied, to facilitate acceleration, and by reason of the all round efliciency ofthe carburetor eliminate many enginetroubles which are liable to occur with known, types, of car buretors.

' According to the present invention a. carburetor is provided'wherein the petrol or equivalent liquid fuel introduced into the mixing chamber is drawn from a fine film of such fuel-,.and a feature resides inproducing an attenuated film of liquid fuel and in causing air to impinge upon, and burst or penetrate said film or fractional parts thereof.

Another feature consists in causing the air to impinge upon and burst or penetrate the film or'parts thereof-and convey the liquid of the film through one or more orifices of small cross section.

A furtherfeature consists in producing the fine film of liquid fuel by one or more conveniently operated members composed of or em-- the float feed chamber-or'other supply and produce; a film of fuel from which film the fuel is deliveredto the mixing chamber by a flow of atmosphere, I

Other features of the invention are included in the construction and arrangement hereinafter more fully described.

For the purpose of more fully describing the nature of this invention reference will now be made to the accompanyingdrawings, wherein I Figure lis arear elevation of one construction of carburetor in accordance with thisi invention. Figure 2 is an end' elevation looking inthe direction Kin-Figure 1. I a I Figure 3 is a sectionalyele'vation on line. A-A'of Figure 2. Figure L is a cross section on line B;B of Figure3; i V

Figure 5 is av front secti onali elevation on Figurefi is a cross sectionion line DD of in Figure 3. U

Figure 7 is a detailwiew showing in,l0ngi-. tudinal section a modified form of throttle valve and air inlet control. r

Figure 8 is an end view looking in the directionYofFigure 7.

Figure 9 is a longitudinal section showing a further modified form of throttlevalve and air inlet control. a Figure 10 is a plan view of Figure, 9. y

'In the embodiment of he invention illustrated in Figures 1' to- 6' the carburetor is provided with a float chamber l 'of any approved or'customary construction, and associated With said float chamber isja vertically an disposed annular compartment 2, which will be designatedthe feedchamber, communicating with the float chamber bya small port '3 at or near the lowermost part of said. feed chamber. I I t Q8 This feed chamber 2 may be provided by forming a circularrecess in a front circular face portion off the main cast metal body'i of thev carburetor, the chamber 2 being-closed by a circular cover plate.5 detachably secured, by screws 5a to thevannular rim of. the cham her and having a central hollow boss 6 proj ecting therefrom rotatably accommodatingv a; spindle 7.

On tl 1is spindle 7 within the feed chamber is or are mounted one or more discs Scomposed wholly or mainly of fine mesh Wire gauze or equivalent finely perforatedor porous material, asmall segment of said disc or discs at the lower part being adapted to dip into petrol delivered from the float chamber 1. For convenience the carburetor will be described as having one disc 8 which is adapted to rotate close to the rear wall of the chamber 2.

In the upper half of the rear Wall of the chamber 2, is a series of small holes 9 conveniently disposed in a vertical or radial line, said holes placing the feed chamber 2 in communication with a tubular mixing chamber or valve chamber 10 which closely accommodates a throttle or control valve, said valve chamber communicating with the induction pipe of an internal combustion engine. By virtue of the provision of a series of discrete or separate, and independent apertures such as indicated at 9 certain disadvantages of other forms of withdrawal apertures are overcome. Where, for example, a continuous slot-shaped withdrawal aperture is used, when the engine is moving at low speeds it is found that the suction is dispersed over the length of the slot, even when the slot is uncoveredbut partially, and that the intensity of the suction is thereby so reduced as to be insufficient and ineffective to penetrate the film of fuel on the disk. However, on account of. the fact that, in accordance with the present invention, independent and disconnected apertures are utilized, when the throttle valve is opened only to a comparatively small extent, and but one or two of the apertures are uncovered, the suction is so concentrated in such uncovered apertures that the intensity of the suction therethrough is found to be effective to penetrate the film on the disk under all working conditions.

The throttle valve 11 may comprise a hollow cylindrical member keyed or pinned to a valve spindle 12 so as to be rotated by lever 13 from any suitable control, the valve having in its circumferential wall a narrow slot 14 which, as the valve is rotated uncovers the part 11 having an integral wall 15 at oneend with air passages'lSa, the other end being closed by a disc 16 connected by pin and slot to the valve spindle 12 so as to rotate in unison therewith but be capable of axial sliding movement thereon. In this disc 16 is an opening 16aapproximately triangular or sector shaped. The open end of the cylindrical part 11 is preferably bevelled or tapered on its exterior face and fits closely within a corresponding taper in the chamber 10.

Adjacent to the valve end disc 16 is a fixed partition 17 having in that half or part nearest to the holes 9 an opening 17 a (Figure 4), the fixing of this partition being conveniently effected by one or more small screws 18.

The throttle valve 11 is held on its tapered seating by a spring 19.

In the front cover 5 of the feed chamber 2 opposite to the said series or row'of holes 9 is an air inlet port 20, which may be fitted with a detachable gauze or other air filter.

The spindle 7 carrying the disc 8 is driven by a flexible shaft as shown in Fig. 6 or other convenient motion transmitting means in suit able ratio to the speed of the engine, say at equal speed, and the operation of the device is as follows Immediately the engine is started the perforated disc 8 is rotated within the feed chamber and the perforations or pores in said disc become filled with the petrol and produce in rotation a fine film of liquid; one or more inwardly projecting radial ribs 21 being suitably positioned on the inner side of the feed chamber cover at a suitable angle to constitute a baflle for preventing the petrol from being thrown up within the chamber and ensuring even distribution over the disc.

As the throttle 11 is'rotated to uncover one or more of the orifices 9 between the feed chamber and throttle chamber, air is drawn in through the aforesaid inlet 20 and, impinging upon the film a petrol opposed thereto on the rotatingdisc, bursts or penetrates said film and conveys the petrol of the film through the orifices9. It may here be said that by virtue of the attenuated nature of the film vaporization of, the liquid by the iinpinging air is achieved in a particularly efiieient manner.

During rotation of the disc petrol carried round thereby may collect within the restricted annular space constituting a. clearance between the circumference of the disc or discs and the feed chamber and provide an effective liquid seal to prevent air from passing through said clearance.

As the throttle is rotated to open same the opening 16a in the throttle end 16 is gradually brought into register with the opening 17a in fixed partition 17 and the side slot 14 successively uncovers the row of perforations 9 until all of same are uncovered and the full 1 extent of the opening 16a registers with the opening 17a. The disc 16 is retained in contact with the partition 17 by suction.

In the arrangement shown in Figure 3 air is admitted into the valve or mixing chamber 10 by way of the holes 15a in the valve wall 15 and a series of holes 22a in the end cover 22 of the chamber, a gauze or other filter 23 beln advantageously provided on the inner si e of holes22a, and if desired, a flexible metal or other disc 24 may also be normally maintained in position over the air holes 22a of the inner face of the cover by a light spring 25, said thin metal disc 24 being drawn away from holes 22a by suction so as to admit air. The aforesaid thin disc 24 may so function as to maintain the air holes 22a covered until a predetermined suction effort is exerted thereon thereby permitting ingress of liquid fuel from the disc chamber 2 prior to the opening of the air inlets 22a so as to facilitate starting up of the engine.

The float chamber 1 conveniently comprises an integral portion of the carburetor body .located beneath the valve chamber 10, the

fioat 26 being carrfed by an arm 27 pivoted at 28 within a centrally slotted rib29, said arm 27 carrying beyond its pivot a vertically slidable needle valve 30 which, as the float 26 7 rises and falls due to varying heights of petrol in the float chamber closes and opens an inlet 31, and automatically controls the flow of petrol from a suitable supply. A screw plug 32 may be provided for obtaining access to the valve 30.

The one end 1a of the float chamber 1 is conveniently cast withthe aforesaid slotted rib 29, inlet passage 31, sockets for screw plug 32 and main petrol pipe connection 33,'

said end cover being removably secured by suitable screws so as to enable same with the aforesaid integral parts to bereadily removed as desired.

For convenience of assembly the end cover 22 of the throttle valve chamber 10 may be clamped in position by a clamping plate 3% having one or more pointed projections 35 at its lower part adapted to engage with a recess or recesses in the end cover 1a of the float chamber, and a bifurcatedupper portion also with inwardly projecting points 36 adapted to coact with recesses in the valve chamber end plate, the clamping plate being assembled upon a fixed screw 37 on the float chamber end and being fixed by a nut 38.

If desired one or more holes 3a additional to the aforesaid hole 3 may be provided in the lower part of the inner wall of the float chamber so as to enable petrol to be supplied to both sides of the disc8, while further holes l Figures 7 and '8 the before descrioed rein tively rotatable disc members 16 and 1"? with openings 16a and 17a are dispensed with and the control of air ingress to the valve chamber 10 is effected by rotating disc ii on the exterior of the end cover 42 of the valve chamber, said end cover and rotating disc having openings 41a and 42a which as said disc all rotated are adapted to be brought into and out of register. The opening lla is preferably of approximately triangular formation so arranged that a comparatively narrow portion thereof is first brought into register with the opening 42a in end cover 42. The movement of the disc a1 is effected simultaneously with the rotation of the throttle from the lever 13, said disc being preferably connected to the lever by means of a screw pin 43 and nut 44, said pin 43 passing through an elongated .slot 45in the lever 13 which slot permits of end disc ll being adjusted relatively to the cover 42 and the throttle valve.

chamber, adjacent to the end cover 42 In the further modification illustrated in *igures 9 and 10 the throttle valve 11 is adapted to function by an axial movement, instead of a rotary movement, the successive opening and closing of the fuel inlet apertures 9 from the feed chamber 2 being effected by providing a triangular shaped opening 47 in the valve wall, it being understood that as the deeper and wider part of the opening moves over the openings 9 more of said openings are uncovered.

Simultaneously with the uncovering of the greater number of the fuel. openings 9, a greater quantity of air is admitted through inlets 48a in an end cover 48, this being accomplished by screwing or otherwise securing on the inner side of said cover an inwardly projecting portion l9 of gradually tapering formation, and causing said member to project through an opening in the one end of the valve 11 in such a manner that the movement of the valve to uncover the aforesaid fuel openings 9 produces an opening in the end of the valve around said projecting member 49 which opening increases in area as the valve moves to uncover a greater number of said fuel openings. Preferably the shape of the tapering member 49 is such as to permit of a predetermined initial movement of the r valve 11 for admitting a limited quantity of fuel through openings 9 prior to the admission of air.

- The requisite motion of the valve maybe efiected by the pivotal displacement of an Kterior lever 50 having an arcuate slot 51 in the central part thereof with which slot engages a headed pin 52 screwed down through an elongated slot 53 in the top of the valve chamber and into athreaded socket 54 in the valve itself. The slot 53 extends parallel with the axis of the valve and chamber and surrounding a plain shank portion of the pin 52 is a roller 55 which runs within said slot 53, a second and smaller roller 56 surrounding the upper part of thepin shank for running within the arcuate slot 51.

a It be said that carburetors constructed in accordance with the present invention are particularly efiicacious for engines running at high speed by virtue'of the fact that as the speed of rotation of the disc 8 increases the n One or more gauze or other filters 46 are preferably provided within the valve film becomes more attenuated, and in consequence petrol consumption is reduced without the elfic1ency of the engine being impaired by virtue of the reduced intake of air resultant upon the increased engine speed.

commodating s id disc, an inlet to such chamber through which air may be drawn by onglne suction to burst or penetrate said film, a mixingchamber, an elongated series of CllS crete apertures between said mixing and said disc chambers through which the atomized mixture is drawn and means for progressive ly opening and closing said apertures.

2. In a carburetor, a rotary disc embodying perforated material, a chamber in which said disc rotates, means for supplying liquid fuel to the lower part of said chamber whereby on rotation of the disc an attenuated film is formed thereon, an air inlet on one wall of the chamber through wl ich air is drawn to burst or penetrate the film, a series of discrete apertures through which the vaporized mixture generated is removed, a mixing chamber communicating with said apertures and means disposed interiorly of the mixing chamber for progressively opening and closing said apertures.

3. In a carburetor, a rotary disc embodying perforated material, a chamber accommodating said disc, means for supplying liquid fuel to said disc, a mixing chamber, a cylindrical rotary throttle valve disposed interiorly of said mixmg chamber, an air inlet to said disc chamber through which air 1s drawn to burst or penetrate said film, a series of discrete apertures communicating between said disc chamber and said mixing chamber for the passage of vaporized mixture, and means operable in unison with the throttle valve functioning progressively .to open and close said series of apertures.

4. In a carburetor, a liquid fuel feed, a rotary disc embodying perforated material, a liquid fuel chamber into which said disc dips, a series of discrete apertures arranged on a radial line in relation to the disc, means for drawing vaporized mixture through said series of apertures and means for progressively rendering said series of apertures inoperative.

5. In a carburetor, a liquid fuel feed, a rotary disc embodying perforated material, a chamber for accommodating said disc, means for supplying liquid to said disc, an inlet to said chamber through which air may pass to burst or penetrate said film, a series of dis crete apertures in said chamber arranged on a radial line in relation to said disc, a mixin g chamber communicating with said apertures into which the vaporized mixture may be drawn from the disc, and means disposed interiorly of said mixing chamber and functioning progressively to render said apertures inoperative.

6. In a carburetor, a rotary disc embodying perforated material, means for supplying liquid fuel to said disc, a chamber for accommodating said disc, air ingress means for said chamber, a series of apertures through which vaporized mixture produced by the air from said ingress bursting or penetrating the film on said disc may be drawn, a mixing chamber communicating with said series of apertures into which the mixture is drawn by engine suction, and a throttle valve in said mixing chamber functioning both to control the admission of additional air to said mixing chamber and progressively to open or close said series of apertures.

7. In a carburetor, a rotary disc embodying perforated material, means for rotating said disc in accordance with the speed of the engine to be fed by the carburetor, a chamber for accommodating said disc, means for supplying liquid fuel to said chamber whereby an attenuated film of liquid may be produced on said disc, an ingress opening through which air may be drawn by engine suction to burst or penetrate said film and produce a vaporized mixture, a series of discrete apertures through which the mixture produced may be drawn off, a mixing chamber communicating with said series of apertures, means for admitting regulable quantities of additional air to said mixing chamber and means for progressively opening or closing said series of apertures.

8. In a carburetor, a rotary disc embodying perforated material, means for supplying liquid fuel to said disc to produce an attenu ated film thereon, a series of discrete apertures arranged substantially on a radial line in relation to said disc through which vaporized mixture may be drawn from the disc, a mixing chamber into which said mixture passes and a member in said mixing chamber adapted primarily to uncover the aperture nearest the centre of the disc and subsequently progressively to open the remaining apertures disposed near the periphery of said disc.

9. In a carburetor, a rotary disc embodying perforated. material, a disc chamber, means for supplying liquid fuel to the lower part of said chamber whereby an attenuated film of liquid is formed on the disc, an inlet to said chamber through which air passes to burst or penetrate the film and produce a vaporized mixture, a series of discrete apertures arranged substantially on. a radial line in relation to said disc through which said 1 I that aperture nearest the centre of the disc in turn to that nearest the periphery thereof.

10. In a carburetor, a rotary disc embodying perforated material, a chamber adapted to accommodate said disc, a float chamber, means for supplying liquid to said chamber, fioat mechanism for maintaining a constant level of liquid in said float chamber, a communicating passage between said float chamher and said disc chamber whereby a constant level of liquid is maintained in the disc chamber said disc dipping into the liquid whereby same is supplied to said disc, an ingress opening in the upper part of said disc chamber through which air is drawn by engine suction to burst or penetrate the film and produce a vaporized mixture, a mixing chamber, a series of apertures communicating between the disc chamber and the mixing chamber arranged on a radial line in relation to said disc, a throttle valve disposed in said mixing chamber, means operable in unison with said throttle valve adapted progressively to uncover said series of apertures, and means operated bysaid throttle valve adapted to admit regulable quantities of additional air to said mixing chamber.

11. In a carburetor, a liquid fuel feed chamber, a liquid supply thereto, a rotary perforated member operating within said feed chamber to produce an attenuated film of liquid, an air ingress to said chamber, a mixing chamber, a displaceable throttle valve in the mixing chamber, an air inlet to the said mixing chamber, the last said air inlet being controlled by the opening and closing movements of the throttle valve, and means for transmitting rotary motion to the perforated disc in the feed chamber in accordance with the speed of the engine to be fed by the car- :i buretor, the opening and closing movements of the throttle valve controlling the suction effect which draws into the feed chamber air which penetrates the liquid film on the disc ind conveys the same into the mixingchamer.

12. In a. carburetor, a rotary disk, means for supplying liquid fuel thereto to produce an attenuated film thereon, a chamber for accommodating the disk, an inlet to the said chamber through which air may be drawn by engine suction to burst the said fuel film, a mixing chamber, an elongated series of apertures between the said mixing and disk chambers through which the atomized mixture is drawn and a valve arranged in the mixing chamber operating to open and close the said apertures, the axes of rotation of the said disk and valve being in planes at right angles to each other.

13. In a carburetor, a rotary disk, a chamber to which fuel is delivered and in Which the said disk is mounted, the disk operating to take up the fuel in the said chamber in the form of an attenuated film thereof, a mixing chamber of cylindrical form, arranged at the mixing chamber and a hollow cylindrical valve mounted within the mixing chamber controlling the opening between the disk and the two chambers.

FREDERICK HUGH SMITH. 

